scholarly journals Surface Manipulation of Thermal-Exfoliated Hexagonal Boron Nitride with Polyaniline for Improving Thermal Stability and Fire Safety Performance of Polymeric Materials

ACS Omega ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 14942-14952 ◽  
Author(s):  
You-Ran Zhi ◽  
Bin Yu ◽  
Anthony Chun Yin Yuen ◽  
Jing Liang ◽  
Lin-Qiang Wang ◽  
...  
Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1093
Author(s):  
Ye Xue ◽  
Xiao Hu

In this study, hexagonal boron nitride (h-BN) nanosheets and Bombyx mori silk fibroin (SF) proteins were combined and electrospun into BNSF nanofibers with different ratios. It was found that the surface morphology and crosslinking density of the nanofibers can be tuned through the mixing ratios. Fourier transform infrared spectroscopy study showed that pure SF electrospun fibers were dominated by random coils and they gradually became α-helical structures with increasing h-BN nanosheet content, which indicates that the structure of the nanofiber material is tunable. Thermal stability of electrospun BNSF nanofibers were largely improved by the good thermal stability of BN, and the strong interactions between BN and SF molecules were revealed by temperature modulated differential scanning calorimetry (TMDSC). With the addition of BN, the boundary water content also decreased, which may be due to the high hydrophobicity of BN. These results indicate that silk-based BN composite nanofibers can be potentially used in biomedical fields or green environmental research.


MRS Advances ◽  
2019 ◽  
Vol 5 (14-15) ◽  
pp. 709-716
Author(s):  
Haley B. Harrison ◽  
Jeffrey R. Alston

AbstractBoron nitride nanotubes (BNNTs) and hexagonal boron nitride platelets (h-BNs) have received considerable attention for aerospace insulation applications due to their exceptional chemical and thermal stability. Presently, making BN nanomaterials compatible with polymer and composite matrices is challenging. Due to their inert and highly stable structure, h-BN and BNNTs are difficult to covalently functionalize. In this work, we present a novel sonochemical technique that enables covalent attachment of fluoroalkoxy substituents to the surface of BN nanomaterials in a controlled and metered process. Covalent functionalization is confirmed via colloidal stability analysis, FT-IR, and x-ray photoelectron spectroscopy (XPS).


Author(s):  
A. Yu. Svatikov ◽  
I. D. Simonov-Emelyanov

Currently, halogen-free cable compositions are becoming increasingly common in the manufacture of cable compositions. The concept of halogen-free or “zero halogen” becomes a symbol of fire resistance, low-smoke characteristics, low toxicity of volatile products of combustion, the absence of the toxic, corrosive and irritating gas - hydrogen chloride - and other hydrogen halides in the volatile products. More and more manufacturers of cable products are beginning to pay increasing attention to the problems of processing, toxicity and fire safety. It should be noted that the requirements for improving the fire safety of cable products are constantly becoming tougher, since the main problem of most of these polymeric materials is their flammability, high smoke generation and high flame spread rate. In this regard, there is a burning question to increase these characteristics and bring them to the level of compounds based on PVC. The main way to increase the flame-retardant characteristics of halogenfree cable compositions is to introduce mineral fire retardants into these compositions. The study of the composition and packaging of these mineral fillers-flame retardants makes it possible to increase the level of flame-retardant characteristics of halogen-free cable compositions. The paper presents the results of studies on the thermal stability of cable compositions based on PE + EVA mixtures containing magnesium hydroxide crystalline hydrate as a filler-flame retardant. It is shown that cable compositions containing magnesium hydroxide crystal hydrate are characterized by higher heat resistance and thermal stability (~ 2-fold) compared to a polymeric matrix based on PE + SEVA. This allows to process them at high temperatures (more than 200°C) by extrusion and pressure casting.


RSC Advances ◽  
2020 ◽  
Vol 10 (27) ◽  
pp. 16088-16093
Author(s):  
Tianyu Zhu ◽  
Yao Liang ◽  
Chitengfei Zhang ◽  
Zegao Wang ◽  
Mingdong Dong ◽  
...  

Large monolayer two-dimensional h-BN can be employed in novel electronic devices because of its thin insulation, excellent thermal stability, and high mechanical strength.


2021 ◽  
Vol 904 ◽  
pp. 202-206
Author(s):  
Jin Du ◽  
Zheng Huan Wu ◽  
Quan Wang

The thermal degradation process of epoxy resin/intumescent flame retardant/flake graphite/hexagonal boron nitride (EP/IFR/FGP/h-BN) was analyzed by thermogravimetry. The effects of binary nano flake graphite/hexagonal boron nitride as synergistic flame retardant on the thermal stability. Flynn wall Ozawa method was used to calculate the activation energy of thermal degradation kinetics of EP/IFR/FGP/h-BN. The mechanism functions of the EP/IFR/FGP/h-BN in different reaction stages were determined according to Malek method, and the thermal degradation mechanism of EP/IFR/FGP/h-BN was obtained. The binary nanoFGP/h-BN is helpful to improve the thermal stability of EP.


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